class Vehicle:
    max_speed = 200 #类变量

    def __init__(self, name, color,speed):
        self.name = name
        self.color = color
        self.speed = speed


    def show(self): 
        print("My name is ",self.name)
        print("My color is ",self.color)
        print("max speed is",self.max_speed)    #类变量的使用
        return

    def run(self):  
        print("My current speed is: ", self.speed)
        return
    
    def modify(self,max):
        self.max_speed = max #类变量的改变

mycar= Vehicle("audi","red",120)
mycar.show()
mycar.modify(180)
mycar.show()